Wait for file transfer/copy to folder completed - using FileSystemWatcher

[bahruddina]

Hi,

I'm trying to get notified by application when the folder is added with new file.

The problem is when the file being added to folder is very big....94 MB. And it takes > 15 minutes to complete the file transfer/copy. And I want only be notified by the application when the file transfer is completed.

Currently I'm just able to get notified whenever the file is added to the folder, even if the file transfer/copy process still not completed

Is there any tips to overcome this problem?

Thank you very much for the help and tips.

regards.

[nemaroller]

An old hack trick, if the file is still being written to... you could not possibly rename the file, it will error saying another process is using it.

So when you do not get an error, you will know the file transfer is complete.

[Cander]

Thats what I do. i kick off a thread when the Systemwatcher kicks in. It is a loop that tries to open the file exclusivly. if it errors, I sleep the thread for 10 seconds, then try again. Wash rinse repeat. Here is my code which has some other stuff you wont need, but should give you an idea

 
Imports System.IO
Imports System.Threading

Module BRS1

    Private fileName As String
    Private myThread As Thread
    Private evLog As EventLog
    Private dir As String = System.Configuration.ConfigurationSettings.AppSettings("Watchdir").ToString()
    Private MonthEnd As Boolean ' Determine if we are waiting for motnh end errors to be corrected.

    Sub Main()
        ' Create a new FilesystemWatcher object
        Console.WriteLine("Type x <Enter> to quit")
        Dim fsWatch As New FileSystemWatcher(dir)
        fsWatch.IncludeSubdirectories = False
        fsWatch.EnableRaisingEvents = True
        AddHandler fsWatch.Created, AddressOf File_Created
        Do Until Console.ReadLine() = "x"

        Loop
    End Sub

    Private Sub File_Created(ByVal sender As Object, ByVal e As System.IO.FileSystemEventArgs)
        ' when the file is created, this event will fire. start a new thread to attempt to open the file.

        fileName = e.FullPath
        myThread = New Thread(AddressOf OpenFileThread)
        myThread.Start()
    End Sub

    Private Sub OpenFileThread()
        Dim openFile As Stream
        Dim fileOpened As Boolean
        Dim boolFileMoved As Boolean
        Dim objFileOps As New BRSFileOperations()
        Dim newFileName As String
        Dim boolValidated As Boolean
        Dim fileGUID As String = Guid.NewGuid.ToString() ' Create a GUID for use in file nameing.
        Dim METhread As Thread

        Do Until fileOpened
            Try
                ' Attempt to open the file.
                openFile = File.Open(fileName, FileMode.Open, FileAccess.ReadWrite, FileShare.None)
                ' If code gets here, move and rename file before processing.
                If Not (boolFileMoved) Then
                    openFile.Close()
                    ' Create new filename
                    newFileName = dir & "\process\" & fileGUID
                    File.Move(fileName, newFileName)
                    boolFileMoved = True
                    fileName = newFileName
                    ' Attempt to open the file again
                    openFile = File.Open(fileName, FileMode.Open, FileAccess.Read, FileShare.None)
                    ' With the boolfilemoved set to true, if it errors above, it should skip this next time
                End If
                Console.WriteLine("Process started at " & System.DateTime.Now())

                ' Validate if the file is a good file
                boolValidated = objFileOps.ValidateFile(openFile)

                ' TODO: Begin Month End wait
                If MonthEnd = True Then
                    METhread = New Thread(AddressOf MonthEndThread)
                    METhread.Start()
                    Do Until MonthEnd = False

                    Loop
                End If
                ' begin parsing if it is valid
                If boolValidated Then
                    objFileOps.ParseFile(openFile)
                End If

                openFile.Close()
                objFileOps = Nothing
                fileOpened = True
            Catch dirnotfound As DirectoryNotFoundException
                ' This should only be thrown during the Move command
                evLog.WriteEntry("Application", dirnotfound.ToString(), EventLogEntryType.Error)
                Thread.CurrentThread.Abort()
            Catch filenotfound As FileNotFoundException
                ' Soemthing happened to the file before we opened it or the process started prematurly.
                ' End this process
                Thread.CurrentThread.Abort()
            Catch fileinuse As IOException
                ' Generic IO Error. No specifc check for file in use.
                Console.WriteLine("Could not open file: " & fileName)
                ' Sleep thread for 10 seconds so it can try again later.
                Thread.CurrentThread.Sleep(10000)
            Catch ex As Exception
                evLog.WriteEntry("Application", ex.ToString(), System.Diagnostics.EventLogEntryType.Error)
                Console.WriteLine(ex.ToString())
                ' Some unknown error. May need to shut the Thread down completey
                Thread.CurrentThread.Abort()
            Finally
                If fileOpened Then
                    ' if everything went ok, then end the thread
                    Console.WriteLine("Process finished at " & System.DateTime.Now())
                    ' TODO: Archive file to zip file for storage
                End If
            End Try
        Loop

        Thread.CurrentThread.Abort()
    End Sub

    Private Sub MonthEndThread()
        ' We need to check every so often if all errors in db has been corrected
        ' Do a cehck.
        ' If errors still exist, sleep for 30 minutes
        ' if 0 found, set motnhend boolen = false and abort thread
        Dim sqlComm As SqlClient.SqlCommand
        Dim conn As System.Data.SqlClient.SqlConnection
        Dim daMonthEnd As SqlClient.SqlDataAdapter
        Dim connstring As String = System.Configuration.ConfigurationSettings.AppSettings("SQLConn").ToString()

        sqlComm = New SqlClient.SqlCommand("Select count(*) from blah")

        Do

            Thread.CurrentThread.Sleep(600000)
        Loop

        Thread.CurrentThread.Abort()
        MonthEnd = False

    End Sub
End Module

[bahruddina]

thanx a lot. It works like a champ